Gluten is a protein found in wheat, rye, barley, spelt, rice, oats, maize and teff. Gluten also occurs in products that are made of these grains. Just think of bread and flour confectionery, etc. The protein of wheat is about 80% of gluten.
What few people know is that glutens are also present to a lesser or greater extent in meat, sweets, bouillon, sauces and ice cream. This is because flours that contain gluten are often used as a binder.
Non-grains such as wild rice, buckwheat, millet, quinoa, amaranth, soybeans and sunflower seeds contain no gluten.
Glutens do not dissolve in water. So it is easy to isolate them from flour made of wheat and other grains. From a simple dough of flour and water, the starch is rinsed out and the gluten is dried. The remaining gluten then has a solid, gum-like structure. Wheat starch is then further processed mainly to glucose syrups.